Add ability to retrieve the shunt voltage if the end user wants to do
the power calculation manually to handle negative power values.
Signed-off-by: Eric Holmberg <eric.holmberg@northriversystems.co.nz>
The current-shunt calibration requires a factor of 4x if high-precision
mode is selected.
Signed-off-by: Eric Holmberg <eric.holmberg@northriversystems.co.nz>
Fix current sign extension logic and consolidate sensor scaling code
into a single block.
Signed-off-by: Eric Holmberg <eric.holmberg@northriversystems.co.nz>
